Poppi collapsed with serious injuries at her home in Barrow-in-Furness, Cumbria, on December 12 2012 and was rushed to hospital, where she was pronounced dead.

Poppi's mother is understandably both distressed and disappointed by the CPS's decision not to bring a prosecution regarding her deathFiona McGhie, lawyer representing Poppi's mother

Mr Worthington was originally arrested on suspicion of sexual assault in August 2013 but no action was taken against him, and he has always denied any wrongdoing.

The toddler's mother was said to be "distressed and disappointed" by the decision not to prosecute.

A CPS spokesman said on Monday: "Following a review of the original charging decision in this case, the CPS announced that there was not a realistic prospect of conviction in July 2016.

"The CPS subsequently received an application under the victims' right to review scheme in September 2016.

"In accordance with the scheme, a CPS lawyer with no prior involvement in the case has completed a full review of the evidence and has concluded that the decision not to charge was correct."

There will be no charges over Poppi Worthington's death

The case has been beset by a series of errors, failures by police and controversial decisions.

The girl's death was shrouded in secrecy, with a 2014 fact-finding civil court judgment by Mr Justice Peter Jackson being kept private so as not to prejudice any criminal proceedings.

An inquest into her death lasted just seven minutes and called no evidence.

Cumbria Police conducted no real investigation for nine months as senior detectives thought a pathologist who examined Poppi's body "may have jumped to conclusions" that the girl had been abused, concluded Mr Justice Jackson.

A list of basic errors in evidence-gathering by detectives was also highlighted, which Cumbria Police later apologised for. Chief Constable Jerry Graham said earlier this year that the initial investigation "fell well short of the standard that could and indeed should have been expected."

A fresh inquest into the death of Poppi - ordered by High Court judges after the first hearing in October 2014 was deemed "irregular" after it called no evidence - had been adjourned pending the latest review.

Mr Justice Peter Jackson made his ruling in the family court Credit:
Gary Lee

Fiona McGhie, a lawyer at Irwin Mitchell, representing Poppi's mother, said on her behalf: "Poppi's mother is understandably both distressed and disappointed by the CPS's decision not to bring a prosecution regarding her death.

"She has always been anxious to know exactly what happened to Poppi on the day of her death as well as to secure justice for her little girl.

"She hopes that an inquest, which was delayed while the CPS examined its decision, will shed some light on Poppi's injuries and create a path to justice so her daughter can finally be at peace."